During integrated circuit fabrication, a plurality of integrated circuits (semiconductor dies) are formed on a single semiconductor wafer simultaneously by a series of material deposition and removal processes. The individual semiconductor dies are then separated from the wafer, in a process called dicing. Wafer dicing generally involves sawing the wafer with a circular saw blade or by scribing and breaking the wafer (if the wafer is crystalline). The portions of the semiconductor wafer where the dies are separated are known as kerfs, or in the parlance of semiconductor manufacturing: streets or scribe streets. Scribe street width is dictated by a combination of wafer properties, blade dimensions and properties, scribe tool dimensions and properties, etc.
One who is of skill in the art will recognize that a conventional scribe street may have a street width of around 62 microns. With a blade or scribe tool width of about 30 microns and a street width of 62 microns, there is only 16 microns clearance on either side of the blade or scribe tool. The semiconductor manufacturing industry, however, is moving toward narrower scribe streets, e.g., 52 microns and below, in an effort to obtain higher die yields per wafer. In order to work with a street width of 52 microns, the blade or scribe tool must be no more than 20 microns thick to maintain the same clearance on either side of the blade. However, reducing the saw blade or scribe tool thickness to enable a narrower kerf has practical limitations.
Accordingly, what is needed in the art is a method for separating a semiconductor wafer into its individual dies that is not limited by the aforementioned thickness.